Navigation systems are available that provide end users with various navigation-related functions and features. For example, some navigation systems are able to determine an optimum route to travel along a road network from an origin location to a destination location in a geographic region. Using input from the end user, the navigation system can examine various potential routes between the origin and destination locations to determine the optimum route. The navigation system may then provide the end user with information about the optimum route in the form of guidance that identifies the maneuvers required to be taken by the end user to travel from the origin to the destination location. Some navigation systems are able to show detailed maps on displays outlining the route, the types of maneuvers to be taken at various locations along the route, locations of certain types of features, and so on.
Some navigations systems may further provide real time traffic data/and or historical traffic data, such as via a map overlay showing such data in relation to the associated roads and/or by factoring such data into travel time or estimated arrival time calculations, e.g. via color codes, etc. Such data is typically provided by a Traffic company. Real time traffic data provides a snapshot of the current traffic conditions on the roads. Historical traffic data, also referred to as “traffic patterns,” provides expected speeds for any given time and day, not taking into account the current conditions. One such Traffic company is Navteq Corporation which provide the Navteq Traffic Patterns™ service. Traffic pattern data may reflect a composite value, such as an average, of the speed measured over a period of time, accounting for various known recurring, cyclical or permanent conditions, e.g. variations in time of day, day of week etc. The result is a service which provides a representation of the expected speed of a road for a variety of conditions.
It will be appreciated, however, that the nature of traffic pattern data as a composite of historical measured values, does not account for conditions or events which were previously unknown, have recently occurred or which are aberrations, i.e. unanticipated, unique and/or temporary, the occurrence of which may have a limited but durable effect on traffic speeds, at least in the near future. For example, a traffic accident may severely impact traffic speeds along a road for several hours after the accident has occurred, and even several hours after it has been cleared.